Encryption/decryption system and method for a mobile device

Abstract

An encryption/decryption system and method are provided for a mobile phone configured to make a voice packet encryption/decryption during mobile communication. The mobile phone has a connecting interface for an external plug-in device. The encryption/decryption system inside the external plug-in device at least has a control unit, and a security chip. When a security communication mode is activated, the communication between users can be prevented from being disclosed. The present invention is to provide the encryption/decryption system and method for activating a security communication mode between two mobile users communicating in mobile communication, and for preventing communication packets from being disclosed.

What is claimed is: 
     
         1 . An encryption/decryption system inside an external plug-in device, the external plug-in device being connected to a mobile phone through a connecting interface of the mobile phone, the encryption/decryption system at least comprising:
 a control unit electrically connected with the mobile phone through the connecting interface; and   a security chip controlled by the control unit, and configured to encrypt a digital code into a digital encrypted package and to decrypt a digital encrypted package into a digital code;   
       wherein the digital code is transmitted from the mobile phone through the connecting interface to the control unit and then from the control unit to the security chip, and the security chip then transmits the digital encrypted package to the mobile phone through the connecting interface via the control unit, and the digital encrypted package is transmitted from the mobile phone through the connecting interface to the control unit and then from the control unit to the security chip and the security chip then transmits the digital code to the mobile phone through the connecting interface via the control unit. 
     
     
         2 . The encryption/decryption system as claimed in  claim 1 , wherein the external plug-in device further comprises a flash memory for a user to store data. 
     
     
         3 . The encryption/decryption system as claimed in  claim 1 , wherein the control unit is configured to be connected to the security chip via a security chip socket. 
     
     
         4 . The encryption/decryption system as claimed in  claim 1 , wherein the security chip further comprises a key system being configured for exchanging keys during communication. 
     
     
         5 . The encryption/decryption system as claimed in  claim 1 , wherein the control unit is further configured to be integrated with the security chip as a multi-function chip. 
     
     
         6 . An encryption/decryption method comprising steps of:
 executing encryption/decryption process;   transmitting digital encrypted package and/or digital code; and   proceeding security communication.   
     
     
         7 . The encryption/decryption method as claimed in  claim 6 , wherein in the executing encryption/decryption process, a security chip encrypts a digital code into a digital encrypted package, the digital code is transmitted from a mobile phone through a connecting interface to the control unit and then from the control unit to the security chip and the security chip then transmits the digital encrypted package to the control unit, the security chip decrypts a digital encrypted package into a digital code, the digital encrypted package is transmitted from the mobile phone through the connecting interface to the control unit and then from the control unit to the security chip, and the security chip then transmits the digital code to the control unit. 
     
     
         8 . The encryption/decryption method as claimed in  claim 6 , wherein in the transmitting digital encrypted package and/or digital code, a control unit transmits a digital encrypted package to a mobile phone through a connecting interface, and the control unit transmits a digital code to the mobile phone through the connecting interface. 
     
     
         9 . The encryption/decryption method as claimed in  claim 6 , wherein in proceeding security communication step, two mobile phones generate random number, exchange random number by PKI, and a security chip of a encryption/decryption system inside an external plug-in device proceeds encryption/decryption processes. 
     
     
         10 . An encryption/decryption method comprising steps of:
 executing encryption/decryption process, wherein a security chip encrypts a digital code into a digital encrypted package, the digital code is transmitted from a mobile phone through a connecting interface to the control unit and then from the control unit to the security chip and the security chip then transmits the digital encrypted package to the control unit, the security chip decrypts a digital encrypted package into a digital code, the digital encrypted package is transmitted from the mobile phone through the connecting interface to the control unit and then from the control unit to the security chip, and the security chip then transmits the digital code to the control unit;   transmitting the digital encrypted package and/or the digital code, where the control unit transmits the digital encrypted package to the mobile phone through the connecting interface, and the control unit transmits the digital code to the mobile phone through the connecting interface; and   proceeding security communication, two mobile phones generate random number, exchange random number by PKI, and the security chip of a encryption/decryption system inside an external plug-in device proceeds encryption/decryption processes.